Underpinning strengthens existing foundations by transferring loads to deeper, more competent ground or by introducing new structural elements to improve stability, capacity, and long‑term performance.
What is underpinning?
Underpinning involves improving or strengthening existing foundations to address settlement, increase load capacity, or accommodate changes in structural demand. These solutions extend foundation support to deeper, more competent soils or introduce new structural elements to share loads. Underpinning is commonly used for existing structures whose foundations no longer meet design or serviceability requirements.
When is underpinning used?
Underpinning may be required when:
- Existing foundations experience settlement or distress
- Additional loads are introduced through building modifications or reuse
- Original foundations were not designed for current conditions
- Adjacent excavation or construction affects foundation stability
- Changes in soil or groundwater conditions reduce bearing capacity
Underpinning is often considered alongside releveling or ground improvement solutions. Releveling restores structural alignment, while underpinning improves long‑term foundation capacity and stability. In many cases, combining these approaches addresses both immediate settlement effects and underlying soil or foundation deficiencies.
Underpinning methods and approaches
Underpinning methods are selected based on existing foundation type, subsurface conditions, access constraints, and project requirements. Solutions may involve extending foundations deeper, installing new structural elements, or transferring loads through alternative load paths. Foundation underpinning techniques bypass the problem soils by installing structural elements to transfer the building’s load to underlying competent soils or bedrock.
Underpinning systems are often installed in restricted environments and may be phased to limit disruption to occupied or operational structures. They can also be designed so that the completed solution is below-grade and the structure's aesthetics are not compromised.
Why choose Keller for underpinning?
Keller combines geotechnical and structural understanding with extensive experience in underpinning existing structures. With multiple underpinning methods available and design-build capability, we develop solutions tailored to access constraints, sequencing needs, and performance objectives while limiting disruption to occupied or operational facilities.
Common uses
- Stabilise structures affected by settlement
- Increase foundation load capacity
- Support renovation, expansion, or change of use
- Protect foundations adjacent to deep excavations
- Stabilize sinkhole conditions
Related projects
Commercial and leisure
KBP Office Building
Keller underpinned the raft foundation of an 8 floors and basement building, by installing Soilcrete® jet grout columns to transfer column loads to competent ground, ensuring long-term foundation stability despite challenging low-headroom access conditions.
Commercial and leisure
Trojena Development – Ski Village
As part of NEOM’s TROJENA development, Keller delivered specialist foundation, slope stabilization, and civil engineering works for the Ski Village, overcoming significant high-altitude construction challenges to support the creation of a world-class mountain resort destination.
Commercial and leisure
Qiddiya Project
Heavy foundation works for an entertainment megaproject to be established in Riyadh.
Energy and utilities
Lifting of Settled Crude Oil Tank
Ground improvement and remediation works for a crude oil tank at a tank farm on an island.
